Diazotypes containing a guanide base in a gelatin layer to prevent dye diffusion



Patented Mar. 13, .1951 r DIAZOTYPES CONTAINING A GUANIDE BASE IN AGELATIN LAYER TO PREVENT DYE DIFFUSION Herman H. Dllerr, Binghamton, N.Y., assignor to General Aniline & Film Corporation, New York, N. Y., acorporation of Delaware No Drawing. Application February 10, 1949,Serial No; 75,737

4 Claims.

The present invention relates to the manufacture of improved sensitivepapers for the produc-.

tion of photographic images by the diazo type process. e

The diazo type process consists of-exposing beneath a pattern a lightsensitive layer containing a light. sensitive diazo compound and acoupling compound on a suitable supporting medium, such.

as paper, whereby the said diazo compound is decomposed whereunprotected by the outlines of the pattern and its ability to combinewith an azo dye coupling component is destroyed. After exposure,development is effected by bringing the exposed layer into contact withgaseous ammonia to cause coupling of the undestroyed diazo compoundandthe coupling component. A replica of the original design is obtained asan azo dye image on light ground. This is known as the dry developingprocess and the sensitive material employed in the process is known asthe dry print paper.

The sensitive (dry print) paper is prepared with a-solution containingboth the diazo-compound and the coupling component on a suitablecarrier, such as textiles, paper, cellulosic films, and the like. Thedyestufi components, as applied on the carrier, are relatively unstableand cannot be stored for long periods of time prior to use, especiallyunder conditions of high humidity. The diazo compound and the couplingcomponent of the sensitized composition tend to difiuse into the carrierlayer, and in the case of a paper base, into the'underlying barytacoating or into the paper fiber. As a consequence of this diffusion, thepaper after exposure and development shows amottled effect. j

. I have found. that the foregoing shortcomings can be obviated byinterposing between the light sensitive layer and thecarrier layer, agelatin layer or other colloid layer containing a guanide or biguanidebase, characterized by the following general formulae:

decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl,heptadecyl, octadecyl, and

the like, benzyl, phenylethyl, phenylpropyl, phenylisopropyl,phenylbutyl, etc., benzoyl, octanoyl, palmit0yl,. cinnamoyl, cumoyl,oleoyl, xyloyl,

. naphthoyl, stearoyl, and the like.

The above bases, wherein R is an alkyl or aralkyl group, are preparedfrom their inorganic salts described in United States Patent 2,149,709

.by rendering an aqueoussolution of such salt alkaline. with sodiumhydroxide, potassium, by droxide, or sodium carbonate and extractingthe) precipitate with a solvent such as ether, toluene or benzene. WhereR is an acyl group, such bases are prepared in the manner from the saltsdescribed in British Patent 546,027.

The following areexamples of the guanide and biguanide bases, which forthe sake of convenience and brevity will be referred to hereinafter asguanide bases prepared in accordance with the methods in the abovepatents:

cmu-Nfi-c-Nn,

Heptylguanide C izHzzs- NHC-NH2 ILIH Dodecylguanide C nHg'r-NiEL-C NHgOctadecylguanide CeH5-OH2NHCNH:

Benzylguanide o1Hno0-NHc-NH,

Caprylylguanide. CnHzu-C O--NHG.Nl-Ia H J Stearoylguanid I C I Egg HHeptylblguanide CH5-CH -NH-C-NHO-NH1 NH' H Benzylbiguanide V CnHzs-C0-NH;-c- NH'- c-NH;

H I H 1 Caprylylbiguanide onus-'0 ONHCNH-CNH2 H Lauroylbiguanide(infirm-magmas, VI H: H

' Dodecylbiguanide CflHg-C O -NH -C NHCNH,' g

M saymiguimde cmHwNn-c NH-cm H H- Octadecylbiguanlde The above guanidebases are dispersed in the form of the alcoholic solutions in a to 7%aqueous solution or dispersion of gelatin or other colloid inan amountranging from 1 to Lxgrams per liter of solution or dispersion and thencoated upon the carrier base, such as opaque paper, paper coated withbaryta, transparentized paper, cellulose acetate film,textile--.cloth,-fiber board, or other suitable carrier base normallyemployed in this art. The gelatin or colloid coating, containing theguanide base, is applied to the carrier base to a dry thickness of,about,3-.6 ma. Over this layer is then coated the usual diazotypetwo-component light sensitive coating com.- position.

By this simple expedient, the intermediate gelatin or colloid layer actsas a barrier between the .base and light sensitive coating compositionand precludes the dyestuff components in said composition from migratingor diffusing into the carrierbase. This markedly overcomes the tendencyto 'form stain and the mottle effect after exposure and development ofthe material.

Either one of the diazo compounds or the coupling components, both ofwhich constitute the dyestuff coatingcomposition-must contain asulfonic, carboxylic, or acid sulfate group. These groups should bepreferablyin thecoupling posi-' tion of the dye coupling component whichis split off during dye couplingiin the developing process.

When the gelatin or colloid coating has been interposed between thecarrier base and light sensitive layer, the diazo compound or thecoupling component or both, containing either sulfonic, carboxylic, oracid sulfate groups, which have migrated to the gelatin coating layerwill form insoluble salts with the guanide base and are thus preventedfrom diffusing into the carrier base. Due to thefact that said acidgroups 4 ethylamino-3 -ethoxy-4amino -benzene, rl-amino-1-benzoylamino-2,5-diethoXy-benzene, p-amino- N-diethylaniline,1-N,N-di(hydroxyethyl) aminoe of the coupling component form a veryinsoluble salt, the groups are precluded from splitting ofi during dyecoupling. Theprecipitated diazo compound or coupling component, or both,at the boundary between the gelatin barrier layer and the lightsensitive layer forms a further barrier'which completely prevents thediffusion of the dyestufi components in the light sensitive layer intothe base.

Although this invention will be particularly described as applied to thetwo-component diazotype process, it is ,to be understood that it can beapplied to the one-component process or moist, or as it is usuallycalled a semi-dry, developingprocess. In this process, the printingpaper is prepared with a solution containing the diazo-body only(generally in the presence of an acid or acid salts). For the developingof this paper, a liquid developer containing in addition to the alkali,also the coupling component, is applied over the" diazo-body coating ina thin layer.

As examples of diazo compounds which are used in the preparation of thetwo-component light sensitive layer and are-in the form of theirstabilized salts, such as the Z1'1C12, CdClz, or SnCh double salts,fiuorborates, aryl or alkyl sulfonates, and acid sulfates of thediazonium compound, those derived from p-diamines of the benzene series,particularly those in which one of the amino groups is substituted bysuch groups as alkyl, alkoxyalkyl, aryl, ar-alkyl, alkylol,cycloaliphatic, and heterocyclic groups may be employed. Examples ofsuch amines are N-hydroxyethyl N methylamino p amino benzene, pamino'dip'h'enyla'mine, :l-m'onoethylamino-2(or 3--) methylAwmino-bentzene,1-N-hydroxyethyl- N+ethylaniino-3-methyl-4-amino-benzene, l-di-.3-chloro-.4-amino-henzene, p-amino-N-ethyl-N- ben'zylaniline; p-amino Ndimethylaniline, 1- ethylamino-4-:arnino-benzene,l-hydroxy-ethylethylaminol-amino benzene, p-phenylene-di- :amine,4-.amino-N;N-dioxyalkylaniline and 4'- etho yphenyle2,5kdiethoxyaniline.

Dye coupling components which may be utilized are legion'and wellknownto those skilled in the art',.and hence an extensive listing of themneed not .be. made herein. It will sufiice to say that compounds of thistype.. comprise phloroglucin, H-acid, pJ-naphthol, resorcin,l-naphthol-3,8 disulfonic acid, 1"-amino-'8naphthol-3,6 disulfenic acid,and'th'elike. V

The following specific examples illustrate several of the variousmethods of preparing the gelatin barrier layers and it will beunderstood that these examples merely represent the pre-' ferredembodiments andare-not to be considered as limitative.

.Example I 1000. of -a 5% solution of dodecylguanide-in methanol weredispersed in 500 cc. of a 1.5%. aqueous solution of gelatin and theresulting solution :coated on'a 'baryta coated' paper to a dry thicknessof approximately 3-4 m i by the usual coating method. Over-this gelatinlayer then was coated the usual light sensitive layer -.con sisting .of"a solution of the diazo compound pphenyleneaminobenzene diazoniumacidsulfate. and acoupling component .2.3-dihydroxynaphthalene. i

Example II Example III cc. of a 10% solution of stearoylbiguanide inmethanol were dispersed in.an.8.% aqueous gelatin solution .containing..5% alum. .Thissolution was used .for top sizing .of the raw printpaper on a paper-making machine. .Overthis gelatin top sizing layerthere was coated the usual light-sensitive layer consisting'of asolution of a diazo compound 2;1-'diazo-hydroxy naphthalene-S-sulfonicacid, and as a coupling compound, J -acid (2,5-aminonaphthol-l-mono-sulfonic acid).

The light sensitive layers prepared according to the above examples didnot show any stain or mottled effect after processing. This was due tothe fact that both dyestufflcomponents failed to diffuse into the baseso thatflno dye was formed therein during development.

It is obvious from the description and'examples' Patent 2,289,775;polyvinyl alcohol and gelling agents as described. in United StatesPatent 2,249,537; polyvinyl acetaldehyde acetal resins and partiallyhydrolyzed acetate resins described in United States Patents 1,939,422and. 2,036,092, and the like, may be employed as dispersing mediums forthe guanide bases, and such" solutions or dispersions utilized ascoatings upon the carrier base or as sizing which is applied to thepaper web during the paper making operation. In lieu of the latter, thecolloid dispersion of the guanide base may be utilized for top sizing ofthe finished paper base.

' By the term carrier as used herein and in the appended claims, I meanthe various materials which have been and are currently used forcarrying the light sensitive material. In the art as presentlydeveloped, these materials comprise paper or vegetable fibers which maybe either transparent, translucent, or opaque. Cloth and films ofcellulose nitrate, cellulose acetate, regenerated cellulose, gelatin andthe like may be employed. Inasmuch as there is no chemical coactionbetween the carrier and the gelatin or other colloid barrier layer, thenature or constitution of the carrier base is immaterial.

I claim: a

1. A light sensitive printing material for use in the production ofdiazotype prints comprising a base coated with a gelatin layer and asuperimposed light sensitive coating comprising a diazo compound and anazo coupling component, at least one of which contains an acid group,and

'6 said gelatin layer containing dispersed therein a guanide base of theclass consisting of the bases having the following general formulae:

wherein R represents a member of the class consisting-of alkyl, aralkyl,and acyl groups of at REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,807,761 Sprongerts June 2, 19311,822,065 Sprongerts et a1. Sept. 8, 1931 2,418,623

Chechak Apr. 8, 1947

1. A LIGHT SENSITIVE PRINTING MATERIAL FOR USE IN THE PRODUCTION OFDIAZOTYPE PRINTS COMPRISING A BASE COATED WITH A GELATIN LAYER AND ASUPERIMPOSED LIGHT SENSITIVE COATING COMPRISING A DIAZO COMPOUND AND ANAZO COUPLING COMPONENT, AT LEAST ONE OF WHICH CONTAINS AN ACID GROUP,AND SAID GELATIN LAYER CONTAINING DISPERSED THEREIN A GUANIDE BASE OFTHE CLASS CONSISTING OF THE BASES HAVING THE FOLLOWING GENERAL FORMULAE: